There is often a need to remove Lewis acid gases from gas mixtures. For example, there is a long-term need to suppress CO2 emissions from the burning of fossil fuels to avoid dangerous anthropogenic interference with the climate system. For example, in 2014, around 2.2 billion tons of CO2 were generated from coal-fired electric power plants in the US, representing 40% of the nation's emissions. There is, therefore, a necessity to stem this release by developing post-combustion carbon capture technologies, which may be added to new plants or retrofitted to existing plants. One technology involves thermal amine scrubbing, which uses cold solutions of amines to bind to CO2 and reverses this binding by elevating the temperature. This was recently implemented at the Boundary Dam power station in Canada, to capture up to 1 million tons of CO2 per year. However, associated with this process is a large enthalpy of reaction and a significant energy cost to release the CO2, as well as heat lost to water vaporization (˜85 kJ mol−1 at 40° C.). In addition, in many power plants (as well as non-power generating industrial processes) there is not always enough steam to operate a thermal swing system.
Accordingly, improved methods and systems are needed.